The impact of foot angle on lower limb muscles activity during the back squat and counter movement jump

BACKGROUND: Squatting is a core exercise for many purposes. However, there is still controversy surrounding the practice of targeting spe-cific muscle groups when performing the back squat with different stance widths or foot positions. Therefore, this study aimed to assess lower limb muscle activation during different form of back squat when adopting three different foot angles.METHODS: Eight male active participants (age: 24.0 +/- 0.8 years, height: 1.80 +/- 0.63 m and mass: 85.8 +/- 8.7kg) performed maximal isometric squat, back squat with an overalod of 80% of 1 repetition maximum, and countermovement jump (CMJ) when adopting three foot rotation angles: parallel (0 degrees), +10 degrees outward (external rotation), and +20 degrees outward (external rotation). We calculated the root mean square of the electro-myographic signals recorded from eight participant's dominant leg muscles.RESULTS: During the descending phase of the back squat, the 20 degrees external foot rotation elicited greater activation of the biceps femoris (+35%; P=0.027) and gastrocnemius medialis (+70%; P=0.040) compared to parallel foot. There were no significant differences among the other mus-cles and exercise conditions. CONCLUSIONS: The +20 degrees foot position increased BF and GasM muscle activity only during the downward phase of the back squat. Strength coaches should consider the present findings when selecting specific resistance exercises aiming to improve athletes' strength and physical fit-ness.(Cite this article as: Rolli F, Vitale JA, Pugliese L, Boccia G, La Torre A, Pollitt L. The impact of foot angle on lower limb muscles activity during the back squat and counter movement jump. J Sports Med Phys Fitness 2022;62:890-7. DOI: 10.23736/S0022-4707.21.12588-5)